[VE] Remove magic numbers 176

Remove magic numbers 176 from VE source codes and update comments.

Reviewed By: simoll

Differential Revision: https://reviews.llvm.org/D91958

lib/Target/VE/VEFrameLowering.cpp

@@ -323,8 +323,8 @@ void VEFrameLowering::emitPrologue(MachineFunction &MF,
   // Get the number of bytes to allocate from the FrameInfo
   uint64_t NumBytes = MFI.getStackSize();
 
-  // The VE ABI requires a reserved 176 bytes area at the top
-  // of stack as described in VESubtarget.cpp.  So, we adjust it here.
+  // The VE ABI requires a reserved area at the top of stack as described
+  // in VESubtarget.cpp.  So, we adjust it here.
   NumBytes = STI.getAdjustedFrameSize(NumBytes);
 
   // Finally, ensure that the size is sufficiently aligned for the

lib/Target/VE/VEISelLowering.cpp

@@ -341,7 +341,7 @@ SDValue VETargetLowering::LowerFormalArguments(
   MachineFunction &MF = DAG.getMachineFunction();
 
   // Get the base offset of the incoming arguments stack space.
-  unsigned ArgsBaseOffset = 176;
+  unsigned ArgsBaseOffset = Subtarget->getRsaSize();
   // Get the size of the preserved arguments area
   unsigned ArgsPreserved = 64;
 
@@ -411,7 +411,7 @@ SDValue VETargetLowering::LowerFormalArguments(
     // The registers are exhausted. This argument was passed on the stack.
     assert(VA.isMemLoc());
     // The CC_VE_Full/Half functions compute stack offsets relative to the
-    // beginning of the arguments area at %fp+176.
+    // beginning of the arguments area at %fp + the size of reserved area.
     unsigned Offset = VA.getLocMemOffset() + ArgsBaseOffset;
     unsigned ValSize = VA.getValVT().getSizeInBits() / 8;
 
@@ -446,7 +446,7 @@ SDValue VETargetLowering::LowerFormalArguments(
   // TODO: need to calculate offset correctly once we support f128.
   unsigned ArgOffset = ArgLocs.size() * 8;
   VEMachineFunctionInfo *FuncInfo = MF.getInfo<VEMachineFunctionInfo>();
-  // Skip the 176 bytes of register save area.
+  // Skip the reserved area at the top of stack.
   FuncInfo->setVarArgsFrameOffset(ArgOffset + ArgsBaseOffset);
 
   return Chain;
@@ -489,7 +489,7 @@ SDValue VETargetLowering::LowerCall(TargetLowering::CallLoweringInfo &CLI,
   CLI.IsTailCall = false;
 
   // Get the base offset of the outgoing arguments stack space.
-  unsigned ArgsBaseOffset = 176;
+  unsigned ArgsBaseOffset = Subtarget->getRsaSize();
   // Get the size of the preserved arguments area
   unsigned ArgsPreserved = 8 * 8u;
 
@@ -631,8 +631,7 @@ SDValue VETargetLowering::LowerCall(TargetLowering::CallLoweringInfo &CLI,
 
     // Create a store off the stack pointer for this argument.
     SDValue StackPtr = DAG.getRegister(VE::SX11, PtrVT);
-    // The argument area starts at %fp+176 in the callee frame,
-    // %sp+176 in ours.
+    // The argument area starts at %fp/%sp + the size of reserved area.
     SDValue PtrOff =
         DAG.getIntPtrConstant(VA.getLocMemOffset() + ArgsBaseOffset, DL);
     PtrOff = DAG.getNode(ISD::ADD, DL, PtrVT, StackPtr, PtrOff);

lib/Target/VE/VEInstrInfo.cpp

@@ -915,8 +915,8 @@ bool VEInstrInfo::expandGetStackTopPseudo(MachineInstr &MI) const {
   const MachineFrameInfo &MFI = MF.getFrameInfo();
   const VEFrameLowering &TFL = *STI.getFrameLowering();
 
-  // The VE ABI requires a reserved 176 bytes area at the top
-  // of stack as described in VESubtarget.cpp.  So, we adjust it here.
+  // The VE ABI requires a reserved area at the top of stack as described
+  // in VEFrameLowering.cpp.  So, we adjust it here.
   unsigned NumBytes = STI.getAdjustedFrameSize(0);
 
   // Also adds the size of parameter area.

lib/Target/VE/VESubtarget.cpp

@@ -50,9 +50,10 @@ VESubtarget::VESubtarget(const Triple &TT, const std::string &CPU,
 uint64_t VESubtarget::getAdjustedFrameSize(uint64_t FrameSize) const {
   // Calculate adjusted frame size by adding the size of RSA frame,
   // return address, and frame poitner as described in VEFrameLowering.cpp.
+  const VEFrameLowering *TFL = getFrameLowering();
 
-  FrameSize += 176;                   // For RSA, RA, and FP.
-  FrameSize = alignTo(FrameSize, 16); // Requires 16 bytes alignment.
+  FrameSize += getRsaSize();
+  FrameSize = alignTo(FrameSize, TFL->getStackAlign());
 
   return FrameSize;
 }

lib/Target/VE/VESubtarget.h

@@ -70,10 +70,14 @@ public:
   VESubtarget &initializeSubtargetDependencies(StringRef CPU, StringRef FS);
 
   /// Given a actual stack size as determined by FrameInfo, this function
-  /// returns adjusted framesize which includes space for register window
-  /// spills and arguments.
+  /// returns adjusted framesize which includes space for RSA, return
+  /// address, and frame poitner.
   uint64_t getAdjustedFrameSize(uint64_t FrameSize) const;
 
+  /// Get the size of RSA, return address, and frame pointer as described
+  /// in VEFrameLowering.cpp.
+  unsigned getRsaSize(void) const { return 176; };
+
   bool isTargetLinux() const { return TargetTriple.isOSLinux(); }
 };